A Study on Two-Dimension Cutting Models of Continuous Chip and Discontinuous Chip

• Main Authors: Lo, Ship-Peng, 羅仕鵬
• Other Authors: Lin, Zone-Ching
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/26780474806089749081

博士 === 國立台灣工業技術學院 === 機械工程技術研究所 === 85 === ABSTRACT The large-deformation strain finite element theory, the updatedLagrangian formulation(ULF) and incremental principles were used inthis paper to develope a two-dimensional thero-elastic-plastic analyticalmodel. In this model, the tool moves forward step by step from the initialtool- workpiece contact till the formation of steady cutting force. Firstly, based on the above model, it was analyzed that OFC copper wasmachined by diamond tool with zero rake angle. The key point is to observethe effects of both cutting speed and temperature to workpiece material.Along the predefined cutting tool path, the geometrical chip separation criterion was used to separate the workpiece node into chip node and machined workpiece node. To understand the effects of the amounts of elastic deformationand crater of cutting tool subjected high cutting force and stressin the chip-tool interface. Under the condition of low cutting speed and no heat transfer, The tool considered as elastic material is the secondstage key point. The iteration mathematical model in the chip-tool interface was developed, and three kinds of tools were applied to machinemild steel workpiece. By using the above iterative model, the effects of different tools under the condition of zero rake angle to cutting processwere investigated. The study of 6-4 copper incipient discontinuous chip formation is thekey point in the final stage. The initial fracture position of chip waspredicted using accumulated strain energy density and the growth orientation of fracture was found using the direction of maximum strain energy density.As a result, the discontinuous chip configuration, cutting force and stress, strain distributions can be obtained.